scholarly journals Investigations of Protective Coatings for Castings of High-Manganese Cast Steels

2013 ◽  
Vol 13 (1) ◽  
pp. 39-44 ◽  
Author(s):  
M. Holtzer ◽  
A. Bobrowski ◽  
D. Drożyński ◽  
J. Mocek
Keyword(s):  
Surface Quality ◽  
Protective Coatings ◽  
Cast Steel ◽  
Small Degree ◽  
Silica Matrix ◽  
Silica Sand ◽  
Hadfield Steel ◽  
High Manganese ◽  
Free Silica ◽  
High Silica

Abstract When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of the so-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel) sands not containing free silica should be applied (e.g. olivine sand) or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2) originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel) and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.

Selection of Protective Coatings of Moulds for Castings of High-Manganese Cast Steel in Dependence of the Applied Moulding Sand Kind

2013 ◽  
Vol 58 (3) ◽  
pp. 853-857
Author(s):  
M. Holtzer ◽  
A. Bobrowski ◽  
D. Drożyński ◽  
J. Mocek
Keyword(s):  
Protective Coatings ◽  
Cast Steel ◽  
Silica Sand ◽  
High Manganese ◽  
Casting Surface ◽  
Hard Materials ◽  
Cast Steels ◽  
High Silica ◽  
Selection Of

Abstract High-manganese cast steels are characterised by a high abrasion resistance under friction conditions with a simultaneous influence of pressure and impacts. This cast steel is especially suitable for castings of excavator’s scoops, track links, streetcars crossovers, parts of crushers and mills for braking up of hard materials [1-4]. In order to obtain high quality castings of high-manganese cast steels in moulds on the high-silica sand matrices it is necessary to apply protective coatings, which prevent a direct contact between metal and matrix (SiO2). Manganese after being poured into a mould can undergo a partial oxidation forming MnO, which reacts with silica. As a result low-melting manganese silicates are formed, which in a form of a tight layer adhere to the casting surface, significantly increasing a labour input related to cleaning. Three kinds of protective coatings were tested: zirconium, corundum and magnesite. As a base moulding sands on high-silica sand matrices with three kinds of resol resins were applied. The quality of the obtained casting surface was assessed in dependence of the protective coating and resin kind and also in dependence of the metallostatic pressure value.

scholarly journals Microstructure of Cast High-Manganese Steel Containing Titanium

2016 ◽  
Vol 16 (4) ◽  
pp. 163-168 ◽  
Author(s):  
G. Tęcza ◽  
A. Garbacz-Klempka
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Cast Steel ◽  
Mining Industry ◽  
Manganese Steel ◽  
Hadfield Steel ◽  
High Manganese ◽  
High Manganese Steel ◽  
The Matrix ◽  
Titanium Carbides

Abstract Widely used in the power and mining industry, cast Hadfield steel is resistant to wear, but only when operating under impact loads. Components made from this alloy exposed to the effect of abrasion under load-free conditions are known to suffer rapid and premature wear. To increase the abrasion resistance of cast high-manganese steel under the conditions where no dynamic loads are operating, primary titanium carbides are formed in the process of cast steel melting, to obtain in the alloy after solidification and heat treatment, the microstructure composed of very hard primary carbides uniformly distributed in the austenitic matrix of a hardness superior to the hardness of common cast Hadfield steel. Hard titanium carbides ultimately improve the wear resistance of components operating under shear conditions. The measured microhardness of the as-cast matrix in samples tested was observed to increase with the increasing content of titanium and was 380 HV0.02 for the content of 0.4%, 410 HV0.02 for the content of 1.5% and 510 HV0.02 for the content of 2 and 2.5%. After solution heat treatment, the microhardness of the matrix was 460÷480 HV0.02 for melts T2, T3 and T6, and 580 HV0.02 for melt T4, and was higher than the values obtained in common cast Hadfield steel (370 HV0.02 in as-cast state and 340÷370 HV0.02 after solution heat treatment). The measured microhardness of alloyed cementite was 1030÷1270 HV0.02; the microhardness of carbides reached even 2650÷4000 HV0.02.

scholarly journals Evaluation of the Possibilities of Sodium Silicate Sands Application in Automated Hot-Box Process of Cores Shooting

2017 ◽  
Vol 17 (4) ◽  
pp. 155-160
Author(s):  
M. Stachowicz ◽  
K. Granat ◽  
P. Obuchowski
Keyword(s):  
Sodium Silicate ◽  
Bending Strength ◽  
Heating Temperature ◽  
Heating Time ◽  
Silica Matrix ◽  
Silica Sand ◽  
Operating Parameters ◽  
High Quality ◽  
High Silica ◽  
Preliminary Research

AbstractThe paper presents the results of preliminary research on the use of silica sands with hydrated sodium silicate 1.5% wt. of binder for the performance of eco-friendly casting cores in hot-box technology. To evaluate the feasibility of high quality casting cores performed by the use of this method, the tests were made with the use of a semiautomatic core shooter using the following operating parameters: initial shooting pressure of 6 bar, shot time 4 s and 2 s, core-box temperature 200, 250 and 300 °C and core heating time 30, 60, 90 and 150 s. Matrixes of the moulding sands were two types of high-silica sand: fine and medium. Moulding sand binder was a commercial, unmodified hydrated sodium silicate having a molar module SiO2/ Na2O of 2.5. In one shot of a core-shooter were made three longitudinal samples (cores) with a total volume of about 2.8 dm3. The samples thus obtained were subjected to an assessment of the effect of shooting parameters, i.e. shooting time, temperature and heating time, using the criteria: core-box fill rate, bending strength (RgU), apparent density and surface quality after hardening. The results of the trials on the use of sodium silicate moluding sands made it possible to further refine the conditions of next research into the improvement of inorganic warm-box / hot-box technology aimed at: reduction of heating temperature and shot time. It was found that the performance of the cores depends on the efficiency of the venting system, shooting time, filling level of a shooting chamber and grains of the silica matrix used.

scholarly journals Cast High-Manganese Steel – the Effect of Microstructure on Abrasive Wear Behaviour in Miller Test

2015 ◽  
Vol 15 (2) ◽  
pp. 35-38 ◽  
Author(s):  
B. Kalandyk ◽  
G. Tęcza ◽  
R. Zapała ◽  
S. Sobula
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Cast Steel ◽  
Abrasive Wear Resistance ◽  
Manganese Steel ◽  
Hadfield Steel ◽  
Wear Behaviour ◽  
Stable Complex ◽  
High Manganese ◽  
High Manganese Steel

Abstract The results of the modification of austenitic matrix in cast high-manganese steel containing 11÷19% Mn with additions of Cr, Ni and Ti were discussed. The introduction of carbide-forming alloying elements to this cast steel leads to the formation in matrix of stable complex carbide phases, which effectively increase the abrasive wear resistance in a mixture of SiC and water. The starting material used in tests was a cast Hadfield steel containing 11% Mn and 1.34% C. The results presented in the article show significant improvement in abrasive wear resistance and hardness owing to the structure modification with additions of Cr and Ti.

Technology for producing composite nanostructured powder for protective coatings

2020 ◽  
pp. 97-103
Author(s):  
E. Yu. Geraschenkova ◽  
A. F. Vasiliev ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Aluminum Powder ◽  
High Speed ◽  
Protective Coatings ◽  
Hadfield Steel ◽  
Nanostructured Powder ◽  
Powder Composition ◽  
Clad Powder

This article presents the results of the development of technology for producing clad powder and coatings based on it. The possibility of obtaining a clad powder using high-speed mechanosynthesis in disintegrator plants is shown on the example of the Hadfield steel – aluminum powder composition.

scholarly journals The Cracking Mechanism of Ferritic-Austenitic Cast Steel

2016 ◽  
Vol 16 (4) ◽  
pp. 153-156 ◽  
Author(s):  
G. Stradomski
Keyword(s):  
Chemical Composition ◽  
Cast Steel ◽  
Hot Cracking ◽  
Hadfield Steel ◽  
Structural Factors ◽  
Low Carbon ◽  
Secondary Phases ◽  
High Tendency ◽  
Iron Manganese ◽  
Low Solubility

Abstract In the high-alloy, ferritic - austenitic (duplex) stainless steels high tendency to cracking, mainly hot-is induced by micro segregation processes and change of crystallization mechanism in its final stage. The article is a continuation of the problems presented in earlier papers [1 - 4]. In the range of high temperature cracking appear one mechanism a decohesion - intergranular however, depending on the chemical composition of the steel, various structural factors decide of the occurrence of hot cracking. The low-carbon and low-alloy cast steel casting hot cracking cause are type II sulphide, in high carbon tool cast steel secondary cementite mesh and / or ledeburite segregated at the grain solidified grains boundaries, in the case of Hadfield steel phosphorus - carbide eutectic, which carrier is iron-manganese and low solubility of phosphorus in high manganese matrix. In duplex cast steel the additional factor increasing the risk of cracking it is very “rich” chemical composition and related with it processes of precipitation of many secondary phases.

scholarly journals Influence of the Reclamation Process Intensity in the REGMAS Reclaimer on the Purification Degree of the High-silica Matrix

2016 ◽  
Vol 16 (1) ◽  
pp. 69-72
Author(s):  
M. Skrzyński ◽  
R. Dańko
Keyword(s):  
Silica Matrix ◽  
High Silica ◽  
Two Stages ◽  
Reclamation Process ◽  
40 Hz

Abstract The investigation results of the reclamation of spent moulding sands with furfuryl resin are presented in this paper. The reclamation process was performed in the secondary reclamation chamber of the REGMAS 1.5 vibratory reclaimer. 70 kg portions of moulding sands, previously subjected to the primary reclamation and dedusting, were used. The secondary reclamation was performed in two stages: the first consisted of determining the reclaimer intensity at various reclamation times (5 min, 10 min and 15 min) and various electrovibrator frequencies (40 Hz, 50 Hz and 60 Hz), the second consisted of determining the influence of additional crushing elements on the intensity of processes.

AN ANALYSYS OF WEAR AND MECHANICAL AND TRIBOLOGICAL PROPERTIES OF HIGH-MANGANESE CAST STEEL HARDENED BY DIFFERENT METHODS

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 137-142
Author(s):  
Dagmara TRYBA ◽  
Marcin KOT ◽  
Anna ANTOSZ
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Cast Steel ◽  
Base Material ◽  
High Manganese ◽  
Dynamic Impact ◽  
Mechanical And Tribological Properties ◽  
Alternative Method

Properties of high manganese austenitic cast steel are not satisfactory; therefore, this material should be hardened. Currently, the commonly used method of hardening does not allow eliminating problems related to premature wear of railway frogs. Therefore, many studies have been carried out to find an alternative method to obtain improved wear resistance of such elements. The article presents an analysis of the mechanical and tribological properties of base and hardened, by different methods, high-manganese cast steel applied for turnouts. Tests were performed for three hardening methods: explosive, pressure-rolling, and dynamic impact. The results were compared with the properties of base material after saturation treatment. The conducted tests allowed the determination of hardness profiles of hardened surfaces, as well as the wear resistance and coefficient of friction, and the obtained results are very promising. Hardening by dynamic impact provided much better results in relation to presently used explosive hardening technology.

Hot Corrosion Resistance Properties of Al-Si Coatings Obtained by Slurry Method

2012 ◽  
Vol 326-328 ◽  
pp. 273-278 ◽  
Author(s):  
Agnieszka Kochmańska
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Hot Corrosion ◽  
Protective Coatings ◽  
Cast Steel ◽  
High Temperature Corrosion ◽  
Air Atmosphere ◽  
Before And After ◽  
Slurry Method ◽  
Thermal Shocks

This paper presents the results of research on aluminide protective coatings manufactured on hightemperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, at carburizing and oxidizing potential atmosphere. Coatings were obtained on cast steel type GXNiCrSi 3018 by slurry cementation in air atmosphere. The tests of carburizing and oxidizing were carried out. The structure of the coatings before and after carburizing and oxidizing is described in the present paper. The chemical composition, thickness and microstructure of coatings were determined. These coatings could protect equipment against hot corrosion at carburizing and oxidizing atmosphere and have thermal shocks resistance.

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